Once upon a time there was a white heron with an injured leg. One day, this white heron happened across a hot spring bursting between the gaps in a rock formation, and soaked its leg in those waters. Over time, his injury began to heal, and when he was well enough, he took flight, leaving the hot spring behind. The people of the surrounding village marveled at the miraculous sight, and when they too soaked in the waters of the hotspring, they found they were able to recover from their aches and pains. Thrilled by the effectiveness of the waters, the villagers did their best to treasure and preserve the spring.
This is the origin of the Dogo Onsen, and this stone is where the white heron is said to have rested. If you observe the stone more closely, you can see what resembles the footsteps of a heron. Were you able to make out the pattern?